#!/usr/bin/env python3

# -- BEGIN LICENSE BLOCK ----------------------------------------------
# Copyright 2021 FZI Forschungszentrum Informatik
# Created on behalf of Universal Robots A/S
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# -- END LICENSE BLOCK ------------------------------------------------
#
# ---------------------------------------------------------------------
# !\file
#
# \author  Felix Exner mauch@fzi.de
# \date    2021-08-05
#
#
# ---------------------------------------------------------------------

import sys

import rospy
import actionlib
from control_msgs.msg import FollowJointTrajectoryAction, FollowJointTrajectoryGoal
from trajectory_msgs.msg import JointTrajectoryPoint
from controller_manager_msgs.srv import SwitchControllerRequest, SwitchController
from controller_manager_msgs.srv import LoadControllerRequest, LoadController
import geometry_msgs.msg as geometry_msgs
from cartesian_control_msgs.msg import (
    FollowCartesianTrajectoryAction,
    FollowCartesianTrajectoryGoal,
    CartesianTrajectoryPoint,
)

# If your robot description is created with a tf_prefix, those would have to be adapted
#如果您的机器人描述是使用 tf_prefix 创建的，则必须对其进行调整 
JOINT_NAMES = [
    "shoulder_pan_joint",
    "shoulder_lift_joint",
    "elbow_joint",
    "wrist_1_joint",
    "wrist_2_joint",
    "wrist_3_joint",
]

# All of those controllers can be used to execute joint-based trajectories.
# The scaled versions should be preferred over the non-scaled versions.
# 所有这些控制器都可以用来执行基于关节的轨迹。
# 缩放版本应优先于非缩放版本。 

JOINT_TRAJECTORY_CONTROLLERS = [
    "scaled_pos_joint_traj_controller",
    "scaled_vel_joint_traj_controller",
    "pos_joint_traj_controller",
    "vel_joint_traj_controller",
    "forward_joint_traj_controller",
]

# All of those controllers can be used to execute Cartesian trajectories.
# The scaled versions should be preferred over the non-scaled versions.
# 所有这些控制器都可以用来执行笛卡尔轨迹。
# 缩放版本应优先于非缩放版本。 
CARTESIAN_TRAJECTORY_CONTROLLERS = [
    "pose_based_cartesian_traj_controller",
    "joint_based_cartesian_traj_controller",
    "forward_cartesian_traj_controller",
]

# We'll have to make sure that none of these controllers are running, as they will
# be conflicting with the joint trajectory controllers
CONFLICTING_CONTROLLERS = ["joint_group_vel_controller", "twist_controller"]


class TrajectoryClient:
    """Small trajectory client to test a joint trajectory"""

    def __init__(self):
        rospy.init_node("test_move_2nd")

        timeout = rospy.Duration(5)
        self.switch_srv = rospy.ServiceProxy(
            "controller_manager/switch_controller", SwitchController
        )
        self.load_srv = rospy.ServiceProxy("controller_manager/load_controller", LoadController)
        try:
            self.switch_srv.wait_for_service(timeout.to_sec())
        except rospy.exceptions.ROSException as err:
            rospy.logerr("Could not reach controller switch service. Msg: {}".format(err))
            sys.exit(-1)

        self.joint_trajectory_controller = JOINT_TRAJECTORY_CONTROLLERS[0]
        self.cartesian_trajectory_controller = CARTESIAN_TRAJECTORY_CONTROLLERS[0]

    def send_joint_trajectory(self):
        """Creates a trajectory and sends it using the selected action server"""

        # make sure the correct controller is loaded and activated
        self.switch_controller(self.joint_trajectory_controller)
        trajectory_client = actionlib.SimpleActionClient(
            "{}/follow_joint_trajectory".format(self.joint_trajectory_controller),
            FollowJointTrajectoryAction,
        )

        # Create and fill trajectory goal
        goal = FollowJointTrajectoryGoal()
        goal.trajectory.joint_names = JOINT_NAMES

        # The following list are arbitrary positions
        # Change to your own needs if desired
        position_list = [[0, -1.57, -1.57, 0, 0, 0]]
        position_list.append([0.2, -1.57, -1.57, 0, 0, 0])
        position_list.append([-0.5, -1.57, -1.2, 0, 0, 0])
        duration_list = [3.0, 7.0, 10.0]
        for i, position in enumerate(position_list):
            point = JointTrajectoryPoint()
            point.positions = position
            point.time_from_start = rospy.Duration(duration_list[i])
            goal.trajectory.points.append(point)

        self.ask_confirmation(position_list)
        rospy.loginfo("Executing trajectory using the {}".format(self.joint_trajectory_controller))

        trajectory_client.send_goal(goal)
        trajectory_client.wait_for_result()

        result = trajectory_client.get_result()
        rospy.loginfo("Trajectory execution finished in state {}".format(result.error_code))

    def send_cartesian_trajectory(self):
        """Creates a Cartesian trajectory and sends it using the selected action server"""
        self.switch_controller(self.cartesian_trajectory_controller)

        # make sure the correct controller is loaded and activated
        goal = FollowCartesianTrajectoryGoal()
        trajectory_client = actionlib.SimpleActionClient(
            "{}/follow_cartesian_trajectory".format(self.cartesian_trajectory_controller),
            FollowCartesianTrajectoryAction,
        )

        # The following list are arbitrary positions
        # Change to your own needs if desired
        pose_list = [
            geometry_msgs.Pose(
                geometry_msgs.Vector3(0.18, -0.18, 0.6), geometry_msgs.Quaternion(0, 0, 0, 1)
            ),
           geometry_msgs.Pose(
                geometry_msgs.Vector3(0.18, -0.18, 0.58), geometry_msgs.Quaternion(0, 0, 0, 1)
            ),
            geometry_msgs.Pose(
                geometry_msgs.Vector3(0.20, -0.18, 0.6), geometry_msgs.Quaternion(0, 0, 0, 1)
            ),
            geometry_msgs.Pose(
                geometry_msgs.Vector3(0.18, -0.20, 0.6), geometry_msgs.Quaternion(0, 0, 0, 1)
            ),
            geometry_msgs.Pose(
                geometry_msgs.Vector3(0.18, -0.18, 0.6), geometry_msgs.Quaternion(0, 0, 0, 1)
            ),
        ]
        duration_list = [3.0, 4.0, 5.0, 6.0, 7.0]
        for i, pose in enumerate(pose_list):
            point = CartesianTrajectoryPoint()
            point.pose = pose
            point.time_from_start = rospy.Duration(duration_list[i])
            goal.trajectory.points.append(point)

        self.ask_confirmation(pose_list)
        rospy.loginfo(
            "Executing trajectory using the {}".format(self.cartesian_trajectory_controller)
        )
        trajectory_client.send_goal(goal)
        trajectory_client.wait_for_result()

        result = trajectory_client.get_result()

        rospy.loginfo("Trajectory execution finished in state {}".format(result.error_code))

    ###############################################################################################
    #                                                                                             #
    # Methods defined below are for the sake of safety / flexibility of this demo script only.    #
    # If you just want to copy the relevant parts to make your own motion script you don't have   #
    # to use / copy all the functions below.                                                       #
    #                                                                                             #
    ###############################################################################################

    def ask_confirmation(self, waypoint_list):
        """Ask the user for confirmation. This function is obviously not necessary, but makes sense
        in a testing script when you know nothing about the user's setup."""
        rospy.logwarn("The robot will move to the following waypoints: \n{}".format(waypoint_list))
        confirmed = False
        valid = False
        while not valid:
            input_str = input(
                "Please confirm that the robot path is clear of obstacles.\n"
                "Keep the EM-Stop available at all times. You are executing\n"
                "the motion at your own risk. Please type 'y' to proceed or 'n' to abort: "
            )
            valid = input_str in ["y", "n"]
            if not valid:
                print("Please confirm by entering 'y' or abort by entering 'n'")
            else:
                confirmed = input_str == "y"
        if not confirmed:
            rospy.loginfo("Exiting as requested by user.")
            sys.exit(0)

    def choose_controller(self):
        """Ask the user to select the desired controller from the available list."""
        print("Available trajectory controllers:")
        for (index, name) in enumerate(JOINT_TRAJECTORY_CONTROLLERS):
            print("{} (joint-based): {}".format(index, name))
        for (index, name) in enumerate(CARTESIAN_TRAJECTORY_CONTROLLERS):
            print("{} (Cartesian): {}".format(index + len(JOINT_TRAJECTORY_CONTROLLERS), name))
        choice = -1
        while choice < 0:
            input_str = input(
                "Please choose a controller by entering its number (Enter '0' if "
                "you are unsure / don't care): "
            )
            try:
                choice = int(input_str)
                if choice < 0 or choice >= len(JOINT_TRAJECTORY_CONTROLLERS) + len(
                    CARTESIAN_TRAJECTORY_CONTROLLERS
                ):
                    print(
                        "{} not inside the list of options. "
                        "Please enter a valid index from the list above.".format(choice)
                    )
                    choice = -1
            except ValueError:
                print("Input is not a valid number. Please try again.")
        if choice < len(JOINT_TRAJECTORY_CONTROLLERS):
            self.joint_trajectory_controller = JOINT_TRAJECTORY_CONTROLLERS[choice]
            return "joint_based"

        self.cartesian_trajectory_controller = CARTESIAN_TRAJECTORY_CONTROLLERS[
            choice - len(JOINT_TRAJECTORY_CONTROLLERS)
        ]
        return "cartesian"

    def switch_controller(self, target_controller):
        """Activates the desired controller and stops all others from the predefined list above"""
        other_controllers = (
            JOINT_TRAJECTORY_CONTROLLERS
            + CARTESIAN_TRAJECTORY_CONTROLLERS
            + CONFLICTING_CONTROLLERS
        )

        other_controllers.remove(target_controller)

        srv = LoadControllerRequest()
        srv.name = target_controller
        self.load_srv(srv)

        srv = SwitchControllerRequest()
        srv.stop_controllers = other_controllers
        srv.start_controllers = [target_controller]
        srv.strictness = SwitchControllerRequest.BEST_EFFORT
        self.switch_srv(srv)


if __name__ == "__main__":
    client = TrajectoryClient()

    # The controller choice is obviously not required to move the robot. It is a part of this demo
    # script in order to show all available trajectory controllers.
    trajectory_type = client.choose_controller()
    if trajectory_type == "joint_based":
        client.send_joint_trajectory()
    elif trajectory_type == "cartesian":
        client.send_cartesian_trajectory()
    else:
        raise ValueError(
            "I only understand types 'joint_based' and 'cartesian', but got '{}'".format(
                trajectory_type
            )
        )
